The invention relates generally to electrical connectors and more particularly to connectors of the plug and socket type having grounded rotating collars such as may be used for electrically and mechanically connecting lengths of cables to each other or to a stationary power supply or machine connector.
Electrical connectors of this type are frequently used in underground mining operations and other locations where it is both desirable and necessary to effect these connections rapidly. In mining operations it is typically required that electrical connectors conform with certain safety standards, such that there be no exposed ungrounded metal surfaces on the connector. Previously known connectors such as shown in U.S. Pat. No. 2,830,282 to Swan et al and, assigned to the same assignee as the present application, exist wherein rotating collars with pin and groove engagement provide for quick electrical and mechanical engagement of the electrical connector. Typically, these types of connectors are thoroughly insulated from electrically live or hot portions of the connector by a barrier of molded rubber or neoprene. The rotating metal collars are also covered with rubber or neoprene so that there are no exposed ungrounded metal components of the electrical connector.
However, in some situations the molded rubber can be cut or scraped off the ungrounded metal collars thereby creating a situation both hazardous and in violation of mining safety regulations. To adequately protect operating personnel, it is necessary to provide an electrical connector wherein the rotating collars are connected through a grounding mechanism to an external grounding source at all times when live power current is supplied to the connector.